Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10415 (Bcl-2)
 33,771 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Parkinson's disease (PD) is characterized by a progressive loss of 70-80% of dopaminergic (DA) neurons in the substantia nigra. High concentrations of DA were suggested to induce oxidative stress and selective neurodegeneration. We evaluated the effect of insulin-like-growth-factor-1 (IGF-1) on DA toxicity in neuronal cultures. IGF-1 (0.5 microg/ml) suppressed cell death induced by exposure to DA (0.3 mM) after 2 and 4 days, in a rat cerebellar culture. Similarly, IGF-1 (0.5 and 1.0 microg/ml) antagonized DA (0.125 and 0.250 mM) neurotoxicity in a human neuroblastoma cell line (SK-N-SH). Flowcytometric analysis of neuroblastoma cells treated with DA (0.5 mM) showed increased apoptosis, which was significantly reduced by IGF-1. The effect of IGF-1 was associated with increased Bcl-2 expression as indicated by flowcytometry and Western blot analysis. We suggest that IGF-1 possesses a neuroprotective effect against DA-induced toxicity, and may have a potential role in the treatment of PD.
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PMID:Protective effect of insulin-like-growth-factor-1 against dopamine-induced neurotoxicity in human and rodent neuronal cultures: possible implications for Parkinson's disease. 1174 19

Studies from our laboratory have demonstrated that the major green tea polyphenol, (-)-epigallocatechin 3-gallate (EGCG), exerts potent neuroprotective actions in the mice model of Parkinson's disease. These studies were extended to neuronal cell culture employing the parkinsonism-inducing neurotoxin, 6-hydroxydopamine (6-OHDA). Pretreatment with EGCG (0.1-10 microm) attenuated human neuroblastoma (NB) SH-SY5Y cell death, induced by a 24-h exposure to 6-OHDA (50 microm). Potential cell signaling candidates involved in this neuroprotective effect were further examined. EGCG restored the reduced protein kinase C (PKC) and extracellular signal-regulated kinases (ERK1/2) activities caused by 6-OHDA toxicity. However, the neuroprotective effect of EGCG on cell survival was abolished by pretreatment with PKC inhibitor GF 109203X (1 microm). Because EGCG increased phosphorylated PKC, we suggest that PKC isoenzymes are involved in the neuroprotective action of EGCG against 6-OHDA. In addition, gene expression analysis revealed that EGCG prevented both the 6-OHDA-induced expression of several mRNAs, such as Bax, Bad, and Mdm2, and the decrease in Bcl-2, Bcl-w, and Bcl-x(L). These results suggest that the neuroprotective mechanism of EGCG against oxidative stress-induced cell death includes stimulation of PKC and modulation of cell survival/cell cycle genes.
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PMID:Involvement of protein kinase C activation and cell survival/ cell cycle genes in green tea polyphenol (-)-epigallocatechin 3-gallate neuroprotective action. 1205 35

In the present study, we tried to clarify the potentially protective role of Bcl-x(L), an anti-apoptotic member of the Bcl-2 family of proteins, in Parkinson's disease (PD). Using in situ hybridization on human postmortem mesencephalon sections, we show that in PD patients Bcl-x(L) mRNA expression per dopaminergic neuron was almost double that of controls. We also show that, ultrastructurally, this effect may be mediated by a redistribution of Bcl-x(L) from the cytosol to the outer mitochondrial membrane.
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PMID:Increased expression and redistribution of the antiapoptotic molecule Bcl-xL in Parkinson's disease. 1207 1

Multiple molecular, cellular, structural, and functional changes occur in the brain during aging. Neural cells may respond to these changes adaptively, or they may succumb to neurodegenerative cascades that result in disorders such as Alzheimer's and Parkinson's diseases. Multiple mechanisms are employed to maintain the integrity of nerve cell circuits and to facilitate responses to environmental demands and promote recovery of function after injury. The mechanisms include production of neurotrophic factors and cytokines, expression of various cell survival-promoting proteins (e.g., protein chaperones, antioxidant enzymes, Bcl-2 and inhibitor of apoptosis proteins), preservation of genomic integrity by telomerase and DNA repair proteins, and mobilization of neural stem cells to replace damaged neurons and glia. The aging process challenges such neuroprotective and neurorestorative mechanisms. Genetic and environmental factors superimposed upon the aging process can determine whether brain aging is successful or unsuccessful. Mutations in genes that cause inherited forms of Alzheimer's disease (amyloid precursor protein and presenilins), Parkinson's disease (alpha-synuclein and Parkin), and trinucleotide repeat disorders (huntingtin, androgen receptor, ataxin, and others) overwhelm endogenous neuroprotective mechanisms; other genes, such as those encoding apolipoprotein E(4), have more subtle effects on brain aging. On the other hand, neuroprotective mechanisms can be bolstered by dietary (caloric restriction and folate and antioxidant supplementation) and behavioral (intellectual and physical activities) modifications. At the cellular and molecular levels, successful brain aging can be facilitated by activating a hormesis response in which neurons increase production of neurotrophic factors and stress proteins. Neural stem cells that reside in the adult brain are also responsive to environmental demands and appear capable of replacing lost or dysfunctional neurons and glial cells, perhaps even in the aging brain. The recent application of modern methods of molecular and cellular biology to the problem of brain aging is revealing a remarkable capacity within brain cells for adaptation to aging and resistance to disease.
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PMID:Modification of brain aging and neurodegenerative disorders by genes, diet, and behavior. 1208 31

In neurodegenerative disorders, such as Parkinson's disease, selective neuronal death characterizes clinical signs and symptoms. Recently apoptosis was reported to be a common type of cell death in some disorders, and well-controlled apoptotic cascade is proposed to be a target of neuroprotective therapy. In our studies to find endogenous neurotoxins as a pathogenic factor in Parkinson's disease, dopamine-derived N-methyl(R)salsolinol was found to induce apoptosis in dopamine neurons of rat models of Parkinson's disease. In human dopaminergic SH-SY5Y cells, apoptosis was initiated by decline in mitochondrial membrane potential, and anti-apoptotic Bcl-2 family protein regulated apoptotic signal transduction. In addition, a series of propargylamines were found to prevent apoptosis through stabilization of mitochondrial membrane potential, which also involved Bcl-2. The role of mitochondria and the involvement of Bcl-2 in apoptosis and neuroprotection were clearly demonstrated using isolated mitochondria. These results indicate that mitochondria are the site to determine the cell death induced by neurotoxins and also the neuroprotection by anti-apoptotic propargylamines.
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PMID:Mitochondria determine the survival and death in apoptosis by an endogenous neurotoxin, N-methyl(R)salsolinol, and neuroprotection by propargylamines. 1211 53

MPTP-induced neurotoxicity is one of the experimental models most commonly used to study the pathogenesis of Parkinson's disease (PD). MPTP administered in vivo to mice causes selective loss of dopaminergic neurons in the substantia nigra (SN), as in this disease. Cell death may be induced in vitro by MPP(+), the active metabolite of MPTP, when neuronal cell cultures are used. Biochemical mechanisms underlying cell death induced by MPTP/MPP(+) still remain to be clarified completely. This article reviews some recent findings linking the effects of MPTP/MPP(+) with molecules typically involved in apoptotic pathways. This type of research has made extensive use of genetically manipulated systems such as transgenic mice and transfected cell lines. Evidence has emerged to suggest that Bcl-2, Bax, JNK, and caspases are implicated in neurotoxic effects due to in vivo MPTP administration to mice. Different neuronal cell lines such as MN9D cells, SH-SY5Y cells, cerebellar granule neurons, cortical neurons, and GH3 cells were also tested to investigate the possible involvement of Bcl-2, Bax, and caspases in in vitro MPP(+)-induced neurotoxicity.
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PMID:Apoptotic molecules and MPTP-induced cell death. 1220 Jan 91

In Parkinson's disease (PD), therapies to delay or suppress the progression of cell death in nigrostriatal dopamine neurons have been proposed by use of various agents. An inhibitor of type B monoamine oxidase (MAO-B), (-)deprenyl (selegiline), was reported to have neuroprotective activity, but clinical trials failed to confirm it. However, the animal and cellular models of PD proved that selegiline protects neurons from cell death. Among selegiline-related propargylamines, (R)(+)-N-propargyl-1-aminoindan (rasagiline) was the most effective to suppress the cell death in in vivo and in vitro experiments. In this paper, the mechanism of the neuroprotection by rasagiline was examined using human dopaminergic SH-SY5Y cells against cell death induced by an endogenous dopaminergic neurotoxin N-methyl(R)salsolinol (NM(R)Sal). NM(R)Sal induced apoptosis (but not necrosis) in SH-SY5Y cells, and the apoptotic cascade was initiated by mitochondrial permeability transition (PT) and activated by stepwise reactions. Rasagiline prevented the PT in mitochondria directly and also indirectly through induction of antiapoptotic Bcl-2 and a neurotrophic factor, glial cell line-derived neurotrophic factor (GDNF). Long-term administration of propargylamines to rats increased the activities of antioxidative enzymes superoxide dismutase (SOD) and catalase in the brain regions containing dopamine neurons. Rasagiline and related propargylamines may rescue degenerating dopamine neurons through inhibiting death signal transduction initiated by mitochondria PT.
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PMID:Neuroprotection by propargylamines in Parkinson's disease: suppression of apoptosis and induction of prosurvival genes. 1220 Jan 98

Our previous studies showed that S-adenosyl-methionine (SAM) induced Parkinson's disease-like changes in rat. It caused death to dopamine neurons in the substantia nigra, which appeared shrunken and fragmented, indicative of apoptosis-like changes (Charlton and Crowell [1995] Mol. Chem. Neuropathol. 26:269-284; Charlton [1997] Life Sci. 61:495-502). In this study, we investigated whether SAM causes apoptosis in both undifferentiated PC12 (PC12) cells and nerve growth factor (NGF)-differentiated PC12 (D-PC12) cells. S-adenosyl-homocysteine (SAH), the nonmethyl analog of SAM, was also tested. SAM and SAH (1.0 nM to 10.0 microM) caused lactate dehydrogenase (LDH) release from the PC12 cells and D-PC12 cells; cells with morphological changes and fluorescent DNA fragmentation staining were detected among both PC12 cell and D-PC12 cell. Compared with the PC12 cell, the D-PC12 cell, a postmitotic cell, was more sensitive to the toxic effects of SAM or SAH and presented much greater LDH release, suggesting a lethal effect; surprisingly, the amounts of apoptotic cells did not differ significantly between the two kinds of cells. In medium deprived of exogenous methionine, a decline in LDH release was observed in PC12 and D-PC12 cells. Also, lower levels of intracellular SAM and SAH were observed in the methionine-deleted media, which were reversed by the addition of either SAM or SAH. An antivitamin B(12) monoclonal antibody was added to methionine-depleted medium, resulting in deficiency of both endogenous and exogenous methionine, which caused further decreases in LDH release and reduction in the levels of intracellular SAM and SAH. The preliminary data showed different sensitivities to SAM or SAH between PC12 cell and D-PC12 cells, which suggests that PC12 cell may be more stable as a metabolic model. Apoptosis of PC12 cells was also assessed by PARP cleavage detection, Western blot analysis of Bax and Bcl-2 proteins, and DNA laddering on agarose gel electrophoresis. The proapoptoic protein Bax was dominantly expressed, whereas Bcl-2 was slightly down-regulated by SAM. SAH weakly induced the expression of Bax and slightly decreased Bcl-2 levels. The effects of SAM and its analog, SAH, were demonstrated conclusively to induce apoptosis in PC12 cells.
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PMID:S-adenosyl-methionine-induced apoptosis in PC12 cells. 1221 Aug 45

Alpha-synuclein (alpha-SN) is a ubiquitous protein that is especially abundant in the brain and has been postulated to play a central role in the pathogenesis of Parkinson's disease, Alzheimer's disease, and other neurodegenerative disorders. However, little is known about the neuronal functions of alpha-SN and the molecular and cellular mechanisms underlying neuronal loss. Here, we show that alpha-SN plays dual roles of neuroprotection and neurotoxicity depending on its concentration or level of expression. At nanomolar concentrations, a-SN protected neurons against serum deprivation, oxidative stress, and excitotoxicity through the PI3/Akt signaling pathway, and its protective effect was increased by Bcl-2 overexpression. Conversely, at both low micromolar and overexpressed levels in the cell, alpha-SN resulted in cytotoxicity. This might be related to decreased Bcl-xL expression and increased bax expression, which is subsequently followed by cytochrome c release and caspase activation and also by microglia-mediated inflammatory responses via the NFkappaB and mitogen-activated protein kinase pathways.
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PMID:Alpha-synuclein regulates neuronal survival via Bcl-2 family expression and PI3/Akt kinase pathway. 1222 45

The role of mitochondrial permeability transition (PT) in apoptosis induced by an endogenous neurotoxin, N-methyl(R)salsolinol [NM(R)Sal], was studied by use of dopaminergic neuroblastoma SH-SY5Y cells. NM(R)Sal reduced mitochondrial membrane potential, DeltaPsim, in the early phase of apoptosis, which was not suppressed by a pan-caspase inhibitor, but was antagonized by Bcl-2 and cyclosporin A, suggesting the involvement of the PT in NM(R)Sal-induced loss of DeltaPsim. NM(R)Sal-induced apoptosis was completely inhibited not only by Bcl-2 and a pan-caspase inhibitor, but also by cyclosporin A, suggesting the essential role of the PT in NM(R)Sal-induced apoptosis. In mitochondria isolated from rat liver, NM(R)Sal induced swelling and reduced DeltaPsim, which was inhibited by cyclosporin A and Bcl-2 overexpression. These results indicate that NM(R)Sal induced the PT by direct action on the mitochondria. Rasagiline, N-propargyl-1(R)-aminoindan, which is a now under a clinical trial for Parkinson's disease, suppressed the DeltaPsim reduction, release of cytochrome c, and apoptosis induced by NM(R)Sal in SH-SY5Y cells. Rasagiline also inhibited the NM(R)Sal-induced loss of DeltaPsim and swelling in the isolated mitochondria, proving that rasagiline directly targets the mitochondria also. Altogether, mitochondrial PT plays a key role both in NM(R)Sal-induced cell death and the neuroprotective effect of rasagiline.
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PMID:Mitochondrial permeability transition mediates apoptosis induced by N-methyl(R)salsolinol, an endogenous neurotoxin, and is inhibited by Bcl-2 and rasagiline, N-propargyl-1(R)-aminoindan. 1235 97


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